Soil erodibility properties experimental quantification: a meta-analysis

The focus in the present study is on the quantification soil erodibility properties (representing an erosion threshold (such as the critical shear stress) and a resistance property (e.g., the soil erosion coefficient)). These are necessary for an adequate assessment of soil erosion mechanisms affecting earth-made hydraulic structures (e.g., dams, dykes and levees). The paper gives a quantitative statistical analysis of the aforementioned soil erodibility parameters. To do so, a wide range of experimental tests, used for the study of internal erosion (hole erosion test (HET) and slot erosion test (SET)) and surface erosion (jet erosion test (JET), flume test (FT), erosion function apparatus (EFA), and rotating cylinder test (RCT)), were examined. A dataset of previously published experimental data was collected, harmonized, structured, treated, and used in a multicriteria analysis. The outcomes of the study provide a better understanding of the limitations and ambiguity in the assessment soil erodibility properties, highlight the differences among tests and between processes, and assess their inter-useability. Correlations between the erodibility properties themselves and between each of them and an in-study-defined midrange soil texture diameters were evaluated at specific level of erosion process, erosion test, and/or soil texture. Furthermore, a set of new empirical formulas has been proposed linking soil erodibility properties to themselves or each erodibility properties to the midrange soil texture diameter. A set of reference values and ranges and trends for the studied erodibility properties, useful for design or risk assessment purposes or for evaluating the quality of experimental data, are derived.